Crustal structure of the eastern Qinling orogenic belt and implication for reactivation since the Cretaceous

Guo, Zhen1,2; Chen, Y. John1,3

2016-06-30

10.1016/j.tecto.2016.06.007

TECTONOPHYSICS   影响因子和分区

0040-1951

1879-3266

A high resolution crustal model of the eastern Qinling belt and central North China Craton (central NCC) is obtained along a N-S trending profile (corridor) by joint inversion of surface wave and receiver function. The NCC is one of the oldest cratons on Earth and the Qinling belt is the suture zone between the NCC and South China block (SCB). The Qinling belt is characterized by low crustal velocity (<3.6 km/s) as well as low bulk Vp/Vs ratio (1.66-1.8), suggesting that the mid- to lower crust is predominantly felsic in composition, which could be the consequence of removal of mafic root by delamination in the past. The quartz-rich hence mechanically weak crust beneath the Qinling belt could be responsible for the strain focusing and significant reactivation since the Cretaceous. Beneath the central NCC, a similar to 10 km thick high-velocity layer (3.9-4.1 km/s) is observed just above the Moho, consistent with the regional high bulk Vp/Vs ratio (>1.8). The forward gravity modeling supports the presence of a high-density layer (3.05 g/cm(3)) at the base of the crust beneath the central NCC. We propose that the high velocity in the lowermost crust beneath the central NCC is most likely due to the repeated mafic underplating, which also results in high crustal Vp/Vs ratio and is responsible for the rapid crustal uplift during the late Mesozoic. (C) 2016 Published by Elsevier B.V.

Surface wave and receiver function joint inversion Gravity modeling Qinling orogenic belt Crustal composition Mafic underplating Delamination

SCI ; EI

英语

通讯

Future Fellowship[FT130101220]

Geochemistry & Geophysics

Geochemistry & Geophysics

WOS:000382343700001

ELSEVIER SCIENCE BV

20162502512208

Delamination ; Structural geology ; Tectonics

Geology:481.1

GEOSCIENCES

Web of Science

1.Peking Univ, Inst Theoret & Appl Geophys, Sch Earth & Space Sci, Beijing, Peoples R China
2.Macquarie Univ, CCFS, GEMOC ARC Natl Key Ctr, Dept Earth & Planetary Sci, Sydney, NSW, Australia
3.South Univ Sci & Technol China, Sch Oceanog, Shenzhen, Peoples R China

Guo, Zhen,Chen, Y. John. Crustal structure of the eastern Qinling orogenic belt and implication for reactivation since the Cretaceous[J]. TECTONOPHYSICS,2016,683:1-11.

Guo, Zhen,&Chen, Y. John.(2016).Crustal structure of the eastern Qinling orogenic belt and implication for reactivation since the Cretaceous.TECTONOPHYSICS,683,1-11.

Guo, Zhen,et al."Crustal structure of the eastern Qinling orogenic belt and implication for reactivation since the Cretaceous".TECTONOPHYSICS 683(2016):1-11.